This invention is concerned with improvements in or relating to the production of surfacing units composed of a plurality of elements of brick, tile, stone or the like and connected by fillets of suitable mortar or other adhesive.
In the production of surfacing units it is known to arrange the component elements in the desired pattern on a base and to maintain them in their correct position, while the gaps between the adjacent edges are filled with mortar or other adhesive, for example by means of suction. The elements are usually placed face-down on the base and, in this way, the accidental application of mortar to the viewable faces is avoided.
While this technique is satisfactory for elements which have a smooth regular surface, obvious difficulties in achieving a satisfactory degree of partial vacuum between the elements and the base are experienced where the elements are provided with a raised pattern or are rough in texture, for example, as in so-called crazypaving. Moreover, where the surfacing unit comprises a corner piece having portions at right angles to other portions thereof, the use of vacuum on such a unit will result in damage to the partially set mortar when the vacuum is released because of the difference in the direction of "spring" between the portions.